asterisk users - Nov 2004 - Call waiting does not work with g729 codec

I have purchased the g729 codec from Digium and I'm using it in
conjunction with Cisco 7905 phones.

When a call is placed to an extension which is in use, instead of
sounding the call waiting tone, it causes an error:

-- Executing Dial("SIP/206.XX.XXX.XXX-08f899d8",
"SIP/204XXXXX83|10") in new stack
-- Called 2044XXXXX83
-- Got SIP response 488 "Not Acceptable Here" back from 192.168.1.112

If I change the codec to ulaw the problem goes away and the tone is
played normally.

There are two issues here:

1) The call waiting codec problem.

2) The error causes asterisk to return a "NOANSWER" status when it
should return something else. More sensible would be BUSY or
UNAVAILABLE.

This is significantly important for me because in this case, when
someone is on the phone the dialplan is supposed to roll-over to the
next available extension. Only when it exhausts all extensions or when
it gets a NOANSWER should it go to voice mail.

In short, BUSY should roll-over. NOANSWER should go to voice mail.

Since the error is returning a NOANSWER status code I can't setup my
dialplan properly.

And one final question, is it possible to disable call waiting?

-- 
John Lange